篩選本土性酵母菌釀造台灣清酒之探討

清酒係以米、米麴、酵母菌及水作為主原料，利用米麴之酵素將米澱粉糖化，同時以酵母菌於酒母中進行並行複式發酵，再以批次式饋料法釀造成清酒，為一種應用微生物發酵之傳統釀造酒類飲品，其以1麴 (製麴米品種及精白率)、2酛 (酒母製作方式及酵母菌) 及3釀造 (發酵參數因子之設定及控制) 描述製成清酒之關鍵主因，而根據文獻指出清酒具有300多種發酵產物，包含糖類、胺基酸、有機酸及香氣化合物。本研究應用微生物技術篩選出本土性酵母菌，選以臺灣粳米品種高雄147號 (Kaohsiung 147 japonica rice) 作為原料，進行釀造臺灣清酒之探討，將高雄147號之白米蒸飯接種市售米麴菌 (Aspergillus oryzae) 製成米麴經分析酵素活性後，再以該品種之白米及發芽糙米 (Germinated brown rice, GBR) 蒸飯，個別接種Lactobacillus plantarum 7-40乳酸桿菌，並分別與經過篩選及鑑定之酵母菌製成共發酵清酒酒母，分析酒母之總菌數、pH值、總酸度、總胺基酸度、可溶性固形物及換算其日本酒度值 (Sake meter value, SMV)，經實驗證實可利用乳酸桿菌所產生之乳酸使pH < 4.6形成酸性酒母，省去清酒製程中需添加之食品添加物乳酸。將發酵完成之酒母擴大培養成10公升之清酒酒醪，於發酵完成後分析清酒之甲醇、乙醇 (酒精度)、葡萄糖、乳酸及γ-胺基丁酸 (γ-Amino Butyric Acid, GABA) 等相關成分，其結果依序分別為甲醇介於70-80 ppm、乙醇 (酒精度) 12-16% (v/v)、葡萄糖含有50-60 mg/100 g、乳酸含有700-800 mg/100 g及GABA含有5-20 mg/100 g之間，再以頂空固相微萃取法 (Headspece-Solid Phase Microextraction, HS-SPME) 於氣相層析串聯質譜儀 (Gas chromatography-mass spectrometry, GC-MS) 中分析自製高雄147號純米酒與高雄147號發芽糙米酒，以及臺灣地區玉泉系列清酒、國立臺灣大學森の藏台灣清酒純米大吟醸、日本地區月桂冠100%特別純米酒以及獺祭系列純米大吟釀等市售清酒之主要香氣化合物，結果發現日本獺祭純米大吟釀 (獺祭23、獺祭39及獺祭45) 所有組別中，皆測得與其他臺灣及日本地區之市售清酒較為缺少之癸酸乙酯 (Ethyl decanoate) 香氣化合物，而自製清酒雖然無使用較高度精白率之米原料，所有組別中亦可測到癸酸乙酯，但與日本獺祭純米大吟釀相比該香氣化合物較為微量。本研究回顧整理出清酒與多元飲食文化酒食 (餐酒) 搭配之可行性模式，期望促進國產稻米糧食之應用性，透過研究糧穀類原料釀酒之相關知識及附加價值等機制，可望促進增加家庭式農民或原住民等小規模糧食生產者之收益及提高農業生產力，以對應聯合國永續發展核心指標 (Sustainable Development Goals, SDGs) 具體目標2.3其中之知識 (knowledge) 與增值 (value addition) 等核心價值。

關鍵字

釀酒酵母菌；乳酸菌共酛酒母；臺灣清酒；頂空固相微萃取法 (HS-SPME) ；粳米高雄147號 (KH147) ；發芽糙米 (GBR)

並列摘要

Sake is made by rice, rice koji, yeast and water as the main raw materials. The rice koji enzyme is used to saccharify the rice starch. At the same time, the yeast is used for multiple parallel fermentation in sake mash, after that sake brewing by fed-batch culture. Sake is a traditionally brewed alcoholic beverage using microorganism fermentation. It is made with the description of 1 koji (the variety of koji rice and the whiteness rate), 2 koji (the brewing method and yeast) and 3 brewing (setting and control of fermentation parameter factors) The main reason for sake is that according to the literature in the before, that was had more than 300 fermentation metabolites, including sugars, amino acids, organic acids and aroma compounds. In this study, we used microbial technology to screening and isolated native yeasts. Taiwanese japonica rice variety of Kaohsiung 147 japonica rice was used as the raw material to study the brewing of Taiwanese sake. After using commercial Aspergillus oryzae koji mold for making rice koji, that analyzing the enzyme activity, steamed rice with white rice and germinated brown rice (GBR) of the same rice variety, individually inoculated with Lactobacillus plantarum 7-40 lactic acid bacteria and selected and identified yeast respectively. The co-fermented sake base is made, and the total bacterial count, pH value, total acidity, total amino acidity, soluble solid content of the sake base are analyzed, and the Japanese sake meter value (SMV) is converted. The produced lactic acid forms an acidic base, and there is no need to add lactic acid as a food additive in the process. Expand the fermented sake mother into 10 liters of sake mash, and analyze the methanol, ethanol (alcohol content), glucose, lactic acid, and γ-Amino Butyric Acid (GABA) of the sake after fermentation. Related ingredients, the results are as follows: methanol is between 70-80 ppm, ethanol (alcohol content) is 12-16% (v/v), glucose contains 50-60 mg/100 g, and lactic acid contains 700-800 mg/100 g and GABA containing between 5-20 mg/100 g, and then headspace solid phase microextraction (Headspece-Solid Phase Microextraction, HS-SPME) in a gas chromatography-mass spectrometry (Gas chromatography-mass spectrometry, GC -MS) Central analysis of the main aromas of homemade Kaohsiung 147 junmai sake and Kaohsiung 147 germinated brown rice wine, as well as the main aromas of commercial sake such as Taiwan Yuchan series sake, NTU Taiwanese junmai daiginjo, Japanese Gekkeikan 100% Yanadanishiki special junmai sake, and Dassai Junmai Daiginjo series (Datsai 23, Datsai 39, and Datsai 45). Theese wwere found that in all groups of Japanese Datsai, ethyl decanoate, which is less than other commercially available sake in Taiwan and Japan, was measured in all groups (Ethyl decanoate) Aromatic compounds. Although homemade sake does not use high-quality rice raw materials, ethyl decanoate can also be detected in all groups. However, compared with Japanese Otaki Pure Rice Daiginjo, this aromatic compound is more Trace amount. In this study that reviews and sorts out the feasibility model for matching sake with diversified food culture and food paring, hoping to promote the applicability of domestic rice and grains. By studying the knowledge and added value mechanism of grains and cereals, it is expected to promote the increase of families. The benefits of small-scale food producers such as family farmers or indigenous peoples and the improvement of agricultural productivity in order to correspond to the United Nations Sustainable Development Goals (SDGs) Target 2.3 The core of knowledge and value addition.